The present invention relates generally to the attachment of one object within a cavity of another object. Specifically, the present invention relates to locking the two objects together when one of the objects may be threaded. More specifically, the present invention permits flexibility in alignment of one object with the other regardless of a particular thread crest position.
One technique for attaching a first object within a second object having a cavity is to incorporate a flange on the first object which is too large to fit through the opening to the cavity. A substantial portion of the first object engages the cavity, but the flange overlaps the opening to the cavity and remains outside the second object. Any number of suitable fasteners may then affix the first object's flange to the outside of the second object. However, this technique is limited to applications where sufficient room exists outside the second object to accommodate the flange portion of the first object.
Another technique for attaching a first object within a cavity in a second object concerns threading. Mated screw threads are formed on the first object and on a cavity wall of the second object. The two objects are attached together by screwing the first object into the second object until the first object is sufficiently locked in place.
This technique may be effective where insufficient room exists outside the second object to accommodate a flange, but is still limited to applications where the cavity is circular in cross sectional area and where the screw threads on the first and second objects are in good shape. Furthermore, controlling the precise angular beginning and depth of threads formed on either the first or second objects may be difficult. Thus, the threading technique is further limited to applications which can tolerate a certain amount of variation in the relative angular orientation of the first object within the cavity of the second object, and the depth to which the first object is displaced within the second object.
Still another technique for attaching a first object within a cavity of a second object uses a suitable adhesive. However, attachment with adhesives is limited to applications where suitable adhesives exist and where removal of the first object from the cavity is not anticipated.
Yet another technique for attaching a first object within a second object having a cavity uses a combination of threading and various inserts. An insert placed inside the cavity may expand as the first object is screwed into it causing attachment of the first object by clamping forces exerted through the deformed insert and against the cavity walls. Alternatively, a slip ring surrounding the first object may be screwed into a threaded cavity also causing attachment through clamping. Since clamping forces are used to attach the two objects together, this technique provides more flexibility in alignment. However, special tools permitting the exertion of great forces on the first and second objects are often required, inserts may not be reusable, and the additional required slip rings and inserts are easily lost.
Accordingly, the present invention provides an attachment apparatus that permits the attachment of a first object within a cavity of a second object without the use of flanges, inserts, or adhesives. Thus, the present invention allows the first object to be mounted entirely within the cavity, does not require the use of components which may be wasted or lost, and permits a multiplicity of removals and re-attachments.
The present invention addresses concerns about the ease of attachment of the first object within the cavity of the second object. Accordingly, the present invention allows mounting the first object within the cavity of the second object without the use of special tools or the application of large forces.
Another facet relates to permitting flexibility in both the angular alignment of the first object relative to the second object and the depth the first object is displaced within the second object. Thus, the present invention may be adapted for use with threading techniques, but it compensates for alignment problems which are characteristic of threading techniques.
The present invention additionally places minimum requirements on the shape of the first object or the cavity in the second object. Consequently, the present invention may be employed with cavities which are not circular in cross-section. Further, if the present invention is used with a threading technique, it remains operative in spite of rusty or damaged threads.
Moreover, the present invention need not damage threads which may exist on either the first or second objects. For example, the present invention may be installed on a first object which substitutes for a plug-like object where the plug-like object screws into a cavity in a second object. The first object which incorporates the present invention may attach within the cavity without damaging the cavity threads and limiting future use of the plug-like object.
Further the present invention indicates by a simple inspection whether the first object is locked within the second object. Unlike adhesive and insert techniques, an installer of an object incorporating the present invention may ascertain that the object is in fact attached without testing the object's resistance to being removed.